Screen: UTF-8 character handling vulnerability
— GLSA 200611-01

Screen contains an error in its UTF-8 character handling code that would
allow a remote Denial of Service or possibly the remote execution of
arbitrary code.

Affected Packages

Package

app-misc/screen on all architectures

Affected versions

< 4.0.3

Unaffected versions

>= 4.0.3

Background

Screen is a full-screen window manager that multiplexes a physical
terminal between several processes, typically interactive shells.

Description

cstone and Richard Felker discovered a flaw in Screen's UTF-8 combining
character handling.

Impact

The vulnerability can be exploited by writing a special string of
characters to a Screen window. A remote attacker could cause a Denial
of Service or possibly execute arbitrary code with the privileges of
the user running Screen through a program being run inside a Screen
session, such as an IRC client or a mail client.